Paullinia yoco R.E. Schult. & Killip - Sapindaceae - yoko, yoco (span.), **Yoko**

Woody climber, native to the rain forests of Southern America (Colombia, Ecuador, Peru); stems up to 12cm in diam. 

"The stem is cut into pieces 30-100cm long, and the epidermis, cortex, and phloem are rasped. The scrapings thus obtained are squeezed to express the caffein-bearing sap into cold water (hot or warm water is never used with yoco), the rasped tissues being then discarded. The liquid, of a cloudy milky-white or light chocolate-brown colour, is drunk cold. The beverage, which is taken early every morning, allays hunger and supplies muscular stimulation. It is also used medicinally as a febrifuge and as a curative for a bilious disease." \\
[Cooper J.M., in Steward J.H., Handbook of South American Indians, Botanical Museum Leaflets No.142 v.5, 1949, 547] 

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The stem cortex of P. yoco is traditionally used by the natives of Colombia and Ecuador to prepare a caffeine-rich beverage. Stem cortex of several yoco types contained up to 0.52% (d.w.), adult leaflets up to 1.3% of caffeine. Theobromine was found up to 0.18% in stem cortex and 0.27% in adult leaflets.\\
[Purine alkaloids in Paullinia., Weckerle, C.S., Stutz, M.A., Baumann, T.W., Phytochemistry, 64(3), 2003, 735-742]